I don't think something like that would move in that way.
First question is "is it in motion, or idling?"

If if it's staying still, it make sway back and forth slowly, or bob up and down, but your is far too active, like it's in a storm. The movement seems to erratic.

Another tip is since the two parts are attached by rope (not like poles) if one part will not move right away (which you appear to know) but if one part moves, it will probably affect the other one. So the cockpit will move one pixel(while the balloon stays) and then the balloon will follow. Like lagging behind. But they will still have the same movement.

When it's moving, it probably would move even less, maybe even an amount too small to represent in pixels.

You also might want to look into sub-pixel movement, I don't know how experienced you are, and it's kinda a hard thing to do, but it's useful for detailing small animations. The basic idea is the moving of a pixel a distance less than a pixel. If that makes any sense. Here is probably the best example I've seen:
Once again, I dunno if you'll be able to do it, but it's an interesting idea. There are probably some tutorials somewhere.


I hope at least some of that made sense....


Edited by skeddles - 02 May 2009 at 6:56pm